Put the G35 folder into your NFSU2 CARS folder.
Run NFSCfgInstaller and look for your NFSU2 folder, then pick the file Lexus SC 300 (JZZ31).u2car in the CFG folder when asked.
With NFS TexEd, open FRONTEND/frontb.lzc and look for ID 83 to replace it with the secondary logo provided.
With NFS LangEd, open your language file in LANGUAGES folder, look for ID 513 and change it to SC300 (JZZ31). Hit Apply and save.

keep this readme file without any alterations whatsoever (in case of just sharing this mod around)
give me proper credit (AJ_Lethal) for creating the mod
Seriously, respecting those conditions is not hard at all. Unless you're terminally dumb or a shameless, talentless hack.